Sizing bullets

[bruce moulds]

I have often wondered if this might be the ideal method, but it takes some work and planning.
forst you would have to anneal the brass to an ideal condition for bpcr pressures, then firefprm it.
obtain a mould/moulds that cast to 0.002 over groove diameter, and cast some bullets.
next, obtain a neck reamer that cuts a hole the exact size of the bullets and ream the case necks.
this will give the bullet an interference fit, and although the tension is theoretically zero, there would be some.
you could possibly finger seat, but might need a die to seat the bullet in the case.
this assumes the chamber is not too loose to achieve, or the brass too thin.
in this case a chamber reamer would need to be purchased. round barrels have some advantages here.
the use of inside neck reamers can be fraught with disaster, as some are more inclined to go crooked than others. this will introduce runout.
neck turning is a better alternative to eliminate bullet runout, but often you have to turn back to where the chamber is tapering with most bpcr bullets, and some chambers taper right to the end.
in these cases fireforming will introduce a taper into th inside of the case, when parralell is preferred.
the reamed fireformed case will have about 0.001 clearance on obturation until the bullet bumps up to that size, and will spring back to an interference fit on pressure release.
this would require constant correct annealing to maintain, but case life would be until the primer pocket actually wears out, which would be virtually indefinitely.
I contacted a reamer manufacturer forster about this, and they did not even acknowledge receipt of email.
probably due to the fact that Australians are not worth 2 knobs of goat shit to this particular American manufacturer, unlike most of them who go out of their way to help us down under.
this technique would be particularly useful when using hornady 405 win brass to make 40/72 or 40/2.5 straight, as it can thicken , and this would make perfect brass.
keep safe,
bruce.